Axenic culture and DNA barcode identification of wood decay fungi from the Maltese Islands

Wood-decaying fungi are important study subjects for their ecological role as well as for their biotechnological applications. They break down lignin, cellulose, and hemicelluloses using enzymes that modify the chemical structure of these complex macromolecules. Due to their ability to degrade wood, these fungi can create structural damage to wooden structures and to trees, especially those with very low level of fitness. Previous studies on wood decay fungi in the Maltese Islands are limited to records and checklists described by a handful of authors. The aim of this study was to provide a comprehensive description of wood decay fungal diversity in the Maltese Islands including an updated checklist based on DNA barcoding, as well as to establish the first wood-decay fungal culture collection at the Biology Department Seed Bank of the University of Malta. Several surveys were carried out during the rainy season along wooded areas of the Maltese Islands as well as in historical gardens. Isolates were identified using macro- and micro-morphological features, dichotomous keys, as well as molecular data. Basidiomes were recorded growing on 14 different host plant species, 11 axenic cultures have been made and 9 species of wood decay fungi have been conclusively identified by DNA barcoding. The collection of the axenic isolates includes one of Aurificaria cf. euphoria, three of Ganoderma resinaceum sl., two of Laetiporus sulphureus, one of Inonotus sp., one of Inonotus rickii anamorph, one of Inocutis tamaricis, one of Stereum hirsutum, and one of Pleurotus eryngii. However, the mycelium of Coriolopsis gallica, though collected and identified, could not be isolated.peer-reviewe

Fomitiporia (Basidiomycota) revisited : species concept, phylogenetic structure and biogeographical patterns

Accurate species delimitations are important to understand factors driving diversification, and have implications for ecological and conservation studies. However, to give a definition of what is a “species”, which would be valid and applicable to all organisms, is challenging. Today the biologists tend to consider the species as a diversified " phenomenon " which can be characterized, morphologically, biologically, genetically, etc. rather than defined in its wholeness. Fungi rise particular problems in the determination of their "status" of species. Their range of intra-specific variations (both genetical and morphological) was poorly studied, what makes very difficult the determination of the significant characters for the establishment of diagnostic criteria. In this study we first tried to integrate the different species concept’s approaches (morphological, phylogenetical, biological, ecological etc.) in order to improve the understanding of “what is a specie” and create a “holistic” species concept. Moreover, the geographical distributions of most fungal species are also still poorly known; consequently, their origins and historical distributions remain largely understudied. High levels of cryptic diversity, scarce fossil records and poorly sampled regions can explain some of these shortcomings. Both issues were developed on an iconic group of wood decaying fungi, the genus Fomitiporia Murrill (Hymenochataceae), which includes parasitic and saprophytic species worldwide distributed. The genus was extensively sampled worldwide , in order to infer evolutionary patterns on a global scale. Fomitiporia, constitutes one of the main genera of poroid Hymenochaetaceae. The particular interest in Fomitiporia also results from the importance of several species as primary etiological agents causing diseases of economically important perennial crops or trees. Taxonomy, phylogeny and biogeography of Fomitiporia were in “chaotic” state of flux. The application of an “holistic” species concept to this genus, allowed us to evidence and at least partially resolve its complex phylogenetic / biogeographic structure. The collecting effort, mostly in tropical or subtropical areas, allow us to gather more than 300 specimens representing 98% of the species actually considered belonging to the genus. Thanks to this integrative approach, seven new species and two new combinations were described, two species proposed as new, three new combination proposed and ultimately fifteen unnamed taxa were evidenced and still need to be described and named in the Linnean system.. Several morphological features, to date considered discriminating at species or genus level, such as the presence of hymenial setae or the dextrinoid basidiospores were demonstrated to be variable characters. Therefore the genus Fomitiporia was redefined on the basis of these findings. Furthermore, this study represent one of the firsts attempts to investigate fungal distributions in an evolutionary context. We used the “state of the art” phylogenetic techniques in order to investigate evolutionary relationships and historical biogeography. Molecular clock dating and ancestral area reconstruction analyses were carried out, as well as the most comprehensive phylogenetic analysis of the genus, based on the most complete taxon sampling to date. The results evidenced, for the first time, several phylogenetic lineages within Fomitiporia, with a strong biogeographical structure, resulting from a complex evolutionary history. Our results suggest a probable Neotropical origin (Palaeocene–Eocene) followed by an early dispersal to the Andean cordillera (Eocene). From the ancestral Neotropical species, the Antarctic land bridge may have provided a corridor for migration between South America and Australia (early Miocene). Subsequently, our data strongly support the hypothesis of a boreotropical dispersal model, from South America to Africa via North America and Eurasia (passing trough the North Atlantic land Bridge). From here, several dispersion events, back and forth to Asia, and ultimately an extreme long-range trans-Atlantic dispersal to the Neotropics, accompanied by a recent radiation were hypothesized.(AGRO - Sciences agronomiques et ingénierie biologique) -- UCL, 201

Fomitiporia castilloi sp. nov. and evidences for multiples clades around F. apiahyna in Meso- and South America, representing potential spec

Fomitiporia castilloi sp. nov. from the lowland rainforest in French Guyana is described, illustrated and its phylogenetic affinities are discussed. This species is characterized by pileate basidiomata, a plicate margin, abundant, variably shaped hymenial setae and basidiospores averaging ≅ 6 × 5 μm. In phylogenetic inferences based on a DNA sequence dataset of four loci (5′ end of the LSU, ITS-5.8S, partial tef1 and rpb2), F. castilloi occupies an isolated position, basal to a clade that is composed exclusively of Neotropical species with resupinate basidiomata. The phylogenetic inferences also provide evidence of an unreported complexity within the Neotropical taxa, with multiple clades closely related to F. apiahyna and F. texana, representing additional potential species

Fomitiporia expansa, an undescribed species from French Guiana

During the revision of the Neotropical Fomitiporia species, a collection from French Guiana was found to represent an undescribed species, on the basis of both morphological and molecular (DNA sequence) data. This taxon is described and illustrated as Fomitiporia expansa sp nov It is characterized by widely effused basidiomata, extending over 1 m long, with a variable greyish to light brownish grey pore surface, and microscopically in having basidiospores averaging 6.0 × 5.5 μm. It is known for the time being from a single specimen originating in the western edge of French Guiana, in rainforest. The species belongs to the Fomitiporia langloisii lineage. This lineage contains for the time being species with resupinate basidiomata spanning over the Neotropics. © 2014 Adac. Tous droits réservés

Fomitiporia baccharidis comb. nov., a little known species from high elevation Andean forests and its affinities within the neotropical Fomitiporia lineages

In the frame of a revision of the Fomitiporia species with pileate basidiomata in the New World, several collections originating from Andean, high elevation forests of Argentina were found to represent a terminal clade in multilocus phylogenetic inferences (including nuclear ribosomal partial LSU and ITS-5.8S, partial tef1-α and RPB2 genes). These collections also represent a singular morphotype within Fomitiporia, characterized by mostly pileate basidiomata, with a soft corky consistency, roughly sulcate pilei, a “duplex” context with a thin black line, and dextrinoid basidiospores, averaging 5.9 × 5.3 μm. It also has a well-marked autecology, occurring on shrubby trees in high elevation forests along the Andean range. A search in the literature for a name pointed toward Phellinus baccharidis, despite the fact that this species was repeatedly described with non-dextrinoid basidiospores. Examination of the type of P. baccharidis confirmed the main morphological features as previously described, but for the reaction of basidiospores in Melzer’s reagent, which was found to be strongly positive (dextrinoid), and an overall similarity with our own specimens; hence, the new combination Fomitiporia baccharidis is proposed. The species is redescribed and illustrated. It is so far known from Argentina and Ecuador. Its phylogenetic relationships with the South American Fomitiporia are briefly discussed

Niveoporofomes (Basidiomycota, Fomitopsidaceae) in Tropical Africa: two additions from Afromontane forests, Niveoporofomes oboensis sp. nov. and N. widdringtoniae comb. nov. and N. globosporus comb. nov. from the Neotropics

During a survey of polypores in the montane forest of the Ôbo de São Tomé National Park, in the western African, equatorial island of São Tomé, a specimen that was, a priori, related to Fomitopsis showed deviating features including subglobose basidiospores with a large gutta. The gross morphology of the basidiome, the hyphal system, the subglobose basidiospores and a brown rot pointed toward Niveoporofomes. Phylogenetic inferences based on multiple loci dataset (ITS-LSU-SSU-TEF1-RPB2) confirmed the placement, and Niveoporofomes oboensis is described as new. The species is compared to Fomitopsis widdringtoniae, known from southeast Africa, which is characterized also by subglobose basidiospores; hence, the new combination N. widdringtoniae is proposed. The new combination Niveoporofomes globosporus (basionym Trametes globospora) is also proposed based on phylogenetic analyses. A key to the species of Fomitopsis, Niveoporofomes, Rhodofomes and Rhodofomitopsis in Tropical Africa is presented

Fomitiporia in sub-Saharan Africa: morphology and multigene phylogenetic analysis support three new species from the Guineo-Congolian rainforest.

Fomitiporia nobilissima sp. nov., F. gabonensis sp. nov. and F. ivindoensis sp. nov., three species from the rainforest of the Guineo-Congolian phytogeographic region in Gabon, are described and illustrated. These species share a pileate basidiome, small basidiospores and an absence of setae. The critical morphological features that differentiate them are the pileus habit or shape, pore surface color, pore diameter and possibly ecology. Each new species forms distinct but closely related clades in phylogenetic analysis of DNA sequences from nuclear ribosomal LSU, ITS and translation elongation factor 1-α. Other species in sub-Saharan Africa are discussed briefly. A key to six species of Fomitiporia from sub-Saharan Africa is provided. The new combination Fomitiporia apiahyna is proposed